Querying and ranking XML documents

Abstract

XML represents both content and structure of documents. Taking advantage of the document structure promises to greatly improve the retrieval precision. In this article, we present a retrieval technique that adopts the similarity measure of the vector space model, incorporates the document structure, and supports structured queries. Our query model is based on tree matching as a simple and elegant means to formulate queries without knowing the exact structure of the data. Using this query model we propose a logical document concept by deciding on the document boundaries at query time. We combine structured queries and term-based ranking by extending the term concept to structural terms that include substructures of queries and documents. The notions of term frequency and inverse document frequency are adapted to logical documents and structural terms. We introduce an efficient technique to calculate all necessary term frequencies and inverse document frequencies at query time. By adjusting parameters of the retrieval process we are able to model two contrary approaches: the classical vector space model, and the original tree matching approach.

Visual exploration and retrieval of XML document collections with the generic system X2

“…The user searches sections talking about the vector space model as well as Information Retrieval in general. As indicated in the upper left corner of the sec slot in Figure 11, the system retrieves 736 sections, each with a relevance score computed according to one of the implemented ranking models, currently either XPRES [27] or s-term [22]. (For a comparison of these and other models, see [26].…”

“…Dedicated ranking schemes for structured document retrieval currently attract much attention in IR research [21,22,8,27,24,26]. X 2 is a system that is to a large extent independent of the ranking mechanism used, hence the research papers mentioned above are complementary to the issues discussed in the paper at hand.…”

A novel XML document structure comparison framework based-on sub-tree commonalities and label semantics

“…Nonetheless, values are usually taken into account with methods dedicated to XML change management [13,14], data integration [29,40], and XML structure-and-content querying applications [66,67], where documents tend to have similar structures (probably conforming to the same grammar [36,83]). …”

XML document-grammar comparison: related problems and applications

“…Here, XML documents tend to have relatively similar structures, and probably conform to the same grammar. With such methods, XML text sequences can be decomposed into words, mapping each word to a leaf node labeled with the respective word [76,77]. Notice that most existing approaches in the context of XML document/grammar comparison disregard element/ attribute values (contents), and mainly focus on heterogeneous document structure comparison (as we will show in the following).…”